雷帕霉素联合紫杉醇对SGC-7901增殖影响的研究

Proliferation effects of combined Rapamycin and paclitaxel on gastric carcinoma cell line SGC-7901 invitro

目的:研究雷帕霉素联合紫杉醇对人胃癌SGC-7901细胞增殖和凋亡的影响。方法:MTT法检测经雷帕霉素、紫杉醇和雷帕霉素+紫杉醇作用后人胃癌SGC-7901细胞的增殖抑制率,流式细胞术检测细胞凋亡率,蛋白质印迹法检测缺氧诱导因子-1α(hypoxia-inducible factor-1alpha,HIF-1α)及血管内皮生长因子(vascular endothelial growth factor,VEGF)蛋白表达,两因素析因设计方差分析法进行统计分析。结果:雷帕霉素、紫杉醇及雷帕霉素联合紫杉醇处理SGC-7901细胞后细胞增殖抑制率分别为(25.43±1.98)%、(27.28±3.34)%和(53.64±1.99)%,雷帕霉素或紫杉醇单独作用均可抑制细胞增殖,联合作用对细胞增殖抑制率影响极显著,F=57.471,P<0.001;两药联合指数>1.15,雷帕霉素和紫杉醇具有协同作用。雷帕霉素、紫杉醇及雷帕霉素联合紫杉醇处理SGC-7901细胞后细胞凋亡率分别为(16.25±1.86)%、(21.80±3.12)%和(38.60±3.78)%,雷帕霉素或紫杉醇单独作用均可诱导细胞凋亡,两药联用细胞凋亡率显著增加,P=0.016 3;雷帕霉素和紫杉醇具有协同诱导SGC-7901细胞凋亡作用。紫杉醇处理细胞后,HIF-1α及VEGF蛋白相对表达量分别为0.598±0.089和0.420±0.091,VEGF蛋白表达下降,P=0.001;而HIF-1α蛋白表达无明显变化,P=0.434。雷帕霉素处理细胞后,HIF-1α及VEGF蛋白相对表达量分别为0.416±0.034和0.376±0.022,表达均显著下降,P值分别为0.016和0.001;而两药联合处理细胞后,HIF-1α及VEGF蛋白相对表达分别为0.209±0.027和0.156±0.015,均显著降低,F值分别为18.322和25.525,P值均为0.001。2种药物对SGC-7901细胞HIF-1α及VEGF蛋白表达抑制起到了显著的协同作用。结论:雷帕霉素联合紫杉醇可显著抑制人胃癌SGC-7901细胞增殖,诱导凋亡,2种药物具有协同抗肿瘤作用。

OBJECTIVE： To study the effect of Rapamycin on proliferation and apoptosis of gastric carcinoma cell line SGC-7901 and the synergic inhibitory effect of combined Rapamycin and paclitaxel on proliferation and apoptosis of SGC-7901 cells. METHODS：Proliferations of gastric cancer cell SGC-7901 were investigated by MTT assay after treated with Rapamycin alone or in combination with paclitaxel, and apoptosis was analyzed by flow cytometry, the expressions of HIF-lα and VEGF were examined by Western blotting technique. The results were analyzed by factorial design variance a- nalysis. RESULTS： In rapamycin, paclitaxel and rapamycin combined paclitaxel treated SGC-7901 cells the cell proliferation inhibition rate of each group were （25.43 ± 1.98）%, （27.28 ± 3.34）% and （53.64 ± 1.99）%. Rapamycin or paclitaxel could inhibit the proliferation of SGC-7901 cells and combinnation of Rapamycin and paclitaxel showed a synergic inhibito- ry effect on the proliferation （F= 57. 471, P〈0. 001）. In rapamycin, paclitaxel and rapamycin combined paclitaxel treated SGC-7901 cells the apoptosis rate of each group were （16.25 ± 1.86）%, （21.80 ± 3.12）% and （38.60 ± 3.78）%. Rapam- ycin or paclitaxel could induced apoptosis of SGC-7901 cells,and combination of Rapamycin and paclitaxel resulted in sig- nificant increased apoptosis of SGC-7901 cells （P=0. 016 3）. The VEGF expression and HIF-la expression were 0. 598± 0. 089 and0. 420±0. 091（P〈0. 001） ,and the HIF-lα expression did not change significanthy （P=0. 434） ,treated by pa- clitaxel,while those were 0. 416 ± 0. 034 and 0. 376 ± 0. 022 treated with rapamycin （P were 0. 016 and 0. 001）. Theexpression of HIF 1 α and VEGF protein of SGC 7901 cells treated by rapamycin combined paclitaxel were 0. 209±0. 027 and 0. 156±0. 015. The expression of HIFla and VEGF were decreased gradually and significantly lower in combined Ra- pamycin and paclitaxel group than that in single paclitaxel or Rapamycin （F= 18. 322, P= 0. 001 and F= 25. 525, P= 0. 001）. CONCLUSIONS：Combined Rapamycin and paclitaxel have a synergistic relation in both inhibition of SGC-7901 cells growth and induction of apoptosis. Rapamycin could suppress the mTOR downstream signaling activation, and en- hanced responses of SGC-7901 cells to paclitaxel.